JP2018165092A - Front vehicle body structure of motor vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a front vehicle body structure which has rigidity characteristics suitable for small overlap collisions and frontal collisions and is light-weight.SOLUTION: The application discloses a front vehicle body structure of a motor vehicle having an impact absorption part which absorbs an impact force. The front vehicle body structure includes: columnar members each having a support front end supporting the impact absorption part and a rear wall located behind the support front end; protruding members protruding outward in a vehicle width direction of the motor vehicle from the columnar members; and front side members, each of which extends forward so as to form a border of a steering space that allows a change of a direction of a front wheel of the motor vehicle and to which the protruding member is attached. The front side member includes: an outer front end which is butted with the rear wall without protruding outward from the rear wall in the vehicle width direction; and an inner front end which is connected to the support front end and located at the inner side relative to the outer front end in the vehicle width direction.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a front body structure that forms a front portion of an automobile.

  A subframe that supports the suspension arm may be disposed below a main frame that forms a part of the vehicle body (see Patent Document 1). The subframe of Patent Document 1 includes a bumper beam, a crash can, a set plate, a front side member, and a protruding member. The bumper beam extends in the vehicle width direction and forms a part of the front end portion of the automobile. The crash can is fixed between the bumper beam and the set plate. The front side member extends rearward from the set plate. The protruding member protrudes outward from the front side member in the vehicle width direction. According to Patent Document 1, when an automobile collides with a portion outside the crash can, the collision object colliding with the automobile hits the protruding member. At this time, the front side member receives a force acting inward in the vehicle width direction from the protruding member, and can be bent or broken. Therefore, the front side member can absorb the impact or block the transmission of the impact force to the passenger compartment. That is, the front vehicle body structure of Patent Document 1 can effectively protect the passenger compartment.

  However, the front body structure of Patent Document 1 can be improved with respect to rigidity against a frontal collision in which the crash can is compressed and deformed. Patent Document 2 proposes to use a columnar member having a three-dimensional shape instead of a planar set plate. According to Patent Document 2, since the columnar member provides high rigidity at the portion where the crash can is supported, the front vehicle body structure of Patent Document 2 can have high rigidity against a frontal collision.

JP 2013-212757 A Japanese Patent Laying-Open No. 2015-231781

  Since the front side member of Patent Document 2 surrounds the rear surface, the right surface, and the left surface of the columnar member, the impact force received by the crash can can be firmly received. However, since the front side member faces the inner surface of the front wheel of the automobile and forms a boundary of the steering space that allows a change in the direction of the front wheel, under the technique of Patent Document 2, the front side member is In this case, the steering space becomes too thick.

  The designer may give the front side member a shape that is greatly curved inward in the vehicle width direction to widen the steering space. However, if the front side member is greatly curved inward, a large stress acts on the curved portion when the automobile collides front, and the front side member is easily damaged. That is, the front side member cannot properly receive a large impact force acting backward.

  A structure that allows the sub-frame to be detached from the main frame when a large impact force acting on the rear acts on the front side member is known (see Japanese Patent Application Laid-Open No. 2014-169043). As a result of the separation of the sub-frame from the main frame, the impact force transmitted to the passenger compartment is greatly reduced.

  With respect to the structure, the connecting portion for connecting the subframe to the main frame is broken by the impact force transmitted through the front side member. However, if the front side member is greatly curved, the front side member may be damaged at the curved portion before the destructive impact force is transmitted to the connecting portion. As a result, the sub-frame is not properly detached from the main frame, and a large impact force may be transmitted to the passenger compartment.

  The designer may increase the rigidity of the front side member itself in order to avoid damage at the curved portion of the front side member. However, the improvement in rigidity tends to result in an increase in the weight of the front side member and an increase in the price of the front side member.

  In the present invention, the front side member is appropriately bent with respect to a collision outside the shock absorbing part (SOL collision: Small Overlap collision), while the front side member is An object of the present invention is to provide a lightweight front vehicle body structure that hardly causes bending and contributes to the formation of a wide steering space.

  A front vehicle body structure according to one aspect of the present invention includes an impact absorbing portion that absorbs an impact force. The front vehicle body structure has a columnar member having a support front end that supports the shock absorbing portion and a rear wall positioned behind the support front end, and protrudes outward in the vehicle width direction of the automobile from the columnar member. And a front side member that extends forward to form a boundary of a steering space that allows a change in the orientation of the front wheels of the automobile and to which the protruding member is attached. The front side member is connected to the outer front end butted against the rear wall without projecting outward from the rear wall in the vehicle width direction, and to the support front end. And an inner front end located inside the outer front end.

  According to said structure, since a columnar member has the support front end to which an impact-absorbing part is attached, and the rear wall located behind the said support front end, it can have higher rigidity than the conventional set plate. . Therefore, when the front vehicle body structure receives a small impact force, only the impact absorbing portion is easily compressed and deformed. This means that unnecessary deformation of the front side member is unlikely to occur.

  Since the protruding member protrudes outward from the columnar member in the vehicle width direction, it can collide with the collision object at the time of the SOL collision. Since the projecting member is attached to the front side member, the front side member receives a force from the projecting member and can be bent or folded appropriately. Therefore, the passenger compartment is easily protected from an impact during a SOL collision.

  When a strong impact force that compresses and deforms the impact absorbing portion acts on the front body structure, the outer front end and the inner front end of the front side member are connected to the rear wall and the support front end of the columnar member, respectively. The member can appropriately receive the impact force. Since the outer front end does not protrude outward in the vehicle width direction from the rear wall of the columnar member, the front side member does not become excessively thick in the vehicle width direction. Therefore, even if the front side member does not have a greatly curved shape, the steering space is widened. Since the front side member can extend rearward substantially straight from the columnar member, the front vehicle body structure can have high rigidity against a frontal collision in which the shock absorbing portion is compressed and deformed.

  With regard to the above configuration, the front side member may include an outer panel extending rearward from the outer front end and an inner panel extending rearward from the inner front end. Each of the outer panel and the inner panel may have a U-shaped cross section. The outer panel may be joined to the inner panel to form a hollow rod used as the front side member.

  According to the above configuration, since the outer panel extending rearward from the outer front end and the inner panel extending rearward from the inner front end have a U-shaped cross section, the hollow rod body used as the front side member is easily formed. The

  With respect to the above configuration, the protruding member may include a rear end edge joined to the outer panel behind the outer front end. The outer panel may include a specifically weakened portion formed at a position behind the rear end edge.

  According to the above configuration, the fragile portion that is particularly fragile is formed at a position rearward of the rear end edge of the projecting member. It becomes easy to bend or break in the weak part.

  With regard to the above configuration, the front vehicle body structure includes a connecting member that connects the columnar member to a vehicle body located above the columnar member, a connection position of the vehicle body and the connecting member, and the rear edge of the protruding member. And a cross member having a rear edge extending inward in the vehicle width direction from the inner panel.

  According to the above configuration, the front vehicle body structure is coupled to the vehicle body by the coupling member via the columnar member. Since the rear edge of the cross member extends inward in the vehicle width direction from the inner panel between the connection position between the vehicle body and the connection member and the rear end edge, it resists the bending moment acting on the front side member. can do. Therefore, the front side member withstands a strong impact force by which the impact absorbing portion is compressed and deformed and is not easily bent. When the SOL collision occurs, the rear edge of the cross member is positioned in front of the rear end edge of the protruding member, so that the front side member can be appropriately bent by the force transmitted from the protruding member.

  With respect to the above configuration, the protruding member may be joined to the outer panel in at least a part of a section from the rear end edge to the outer front end. The rear wall may include a first region against which the outer front end is abutted, and a second region adjacent to the first region and covered by the protruding member.

  According to the above configuration, the outer front end is abutted against the first region, while the second region adjacent to the first region is covered by the protruding member, so the outer front end is from the rear wall of the columnar member, Does not protrude outward in the vehicle width direction. Since the front side member does not become excessively thick in the vehicle width direction, the steering space becomes wide even if the front side member does not have a greatly curved shape. Since the front side member can extend rearward substantially straight from the columnar member, the front vehicle body structure can have high rigidity against a frontal collision in which the shock absorbing portion is compressed and deformed.

  With regard to the above configuration, the columnar member includes an inner wall joined to the inner panel projecting forward from the outer front end, and an outer wall located on the opposite side of the inner wall and to which the projecting member is joined. And may be included. The support front end may include an inner mounting wall bent inward in the vehicle width direction from the inner wall, and an outer mounting wall bent outward in the vehicle width direction from the outer wall. Good. The inner front end may be joined to the inner mounting wall. The protruding member may be joined to the outer wall.

  According to the above configuration, the inner wall is joined to the inner panel projecting forward from the outer front end, while the outer wall is joined to the projecting member, so that about half of the peripheral surface of the columnar member is the front It is surrounded by the side member, and about half of the peripheral surface of the columnar member is surrounded by the protruding member. Therefore, the columnar member is not easily deformed even when a large impact force is applied. The outer mounting wall bent outward in the vehicle width direction is joined to the projecting member, and the inner front end of the front side member is joined to the inner mounting wall, so that the periphery of the connecting member when a SOL collision occurs This moment is effectively converted into a force that bends the front side member inward in the vehicle width direction.

  With respect to the above configuration, the hollow rod body may have a size larger in the vertical direction than in the vehicle width direction.

  With respect to the above configuration, the hollow rod body has a larger dimension in the vertical direction than in the vehicle width direction. Therefore, even if the front side member is thin in the vehicle width direction, it can have a large rigidity.

  The front vehicle body structure described above can appropriately bend the front side member with respect to the SOL collision, while making it difficult for the front side member to be bent with respect to the collision that compressively deforms the shock absorbing portion. In addition, the front vehicle body structure is lightweight and can contribute to the formation of a wide steering space.

It is a schematic perspective view of a subframe exemplified as a front body structure. FIG. 2 is an enlarged horizontal sectional view of the subframe shown in FIG. 1. FIG. 2 is a schematic exploded perspective view of a subframe shown in FIG. 1. FIG. 2 is a schematic plan view of a front side member of a subframe shown in FIG. 1. FIG. 5 is a schematic horizontal sectional view of a part of a left wall portion of a left panel of the subframe shown in FIG. 4. FIG. 2 is a schematic side view of a subframe shown in FIG. 1. FIG. 2 is a schematic plan view of a part of a subframe shown in FIG. 1.

  FIG. 1 is a schematic perspective view of a subframe 100 exemplified as a front vehicle body structure. With reference to FIG. 1, a subframe 100 is described.

  The subframe 100 has a symmetrical structure. The structure on the left side of the subframe 100 will be mainly described. The description regarding the structure on the left side of the subframe 100 is incorporated in the structure on the right side of the subframe 100.

  Regarding the structure on the left side, the term “left” means outward in the vehicle width direction. The term “right” means inward in the vehicle width direction. As described above, since the subframe 100 has a symmetrical structure, the outer side in the vehicle width direction is “right” and the inner side in the vehicle width direction is the right side of the subframe 100. , “Left”.

  The subframe 100 includes two crush cans 111 and 112, two set plates 121 and 122, two columnar members 131 and 132, two projecting members 141 and 142, and two front side members 151 and 152. A bumper beam 160 and a support structure 170. FIG. 1 shows two lower arms LAL and LAR. The support structure 170 supports the two lower arms LAL and LAR. The left lower arm LAL is connected to a left front wheel (not shown). The right lower arm LAR is connected to the right front wheel (not shown).

  The front side members 151 and 152 extend forward from the support structure 170 and are connected to the columnar members 131 and 132, respectively. The front side member 151 is located on the left side of the front side member 152. The columnar member 131 is located on the left side of the columnar member 132. The space on the left side of the front side member 151 is used as a steering space used for changing the direction of the left front wheel. The front side member 151 forms a boundary of the left front wheel steering space. The space on the right side of the front side member 152 is used as a steering space that is used to change the direction of the right front wheel. The front side member 152 forms a boundary of the steering space for the right front wheel.

  The left protruding member 141 is connected to the front side member 151 and the columnar member 131. The protruding member 141 protrudes leftward from the front side member 151 and the columnar member 131. The right protruding member 142 is connected to the front side member 152 and the columnar member 132. The protruding member 142 protrudes rightward from the front side member 152 and the columnar member 132.

  The left columnar member 131 is located between the front side member 151 and the set plate 121. The columnar member 131 protrudes upward from the front side member 151, the set plate 121, and the protruding member 141, and is connected to a vehicle body (not shown) positioned above the subframe 100. The lower part of the columnar member 131 is surrounded by the front side member 151, the set plate 121, and the protruding member 141.

  The right columnar member 132 is located between the front side member 152 and the set plate 122. The columnar member 132 protrudes upward from the front side member 152, the set plate 122, and the protruding member 142, and is connected to a vehicle body (not shown) positioned above the subframe 100. The lower part of the columnar member 132 is surrounded by the front side member 152, the set plate 122, and the protruding member 142.

  The rear end of the crash can 111 is connected to the set plate 121. The set plate 121 is connected to the columnar member 131. Therefore, the crash can 111 is attached to the columnar member 131 via the set plate 121. The front end of the crash can 111 is connected to the vicinity of the left end of the bumper beam 160.

  The rear end of the crash can 112 is connected to the set plate 122. The set plate 122 is connected to the columnar member 132. Therefore, the crash can 112 is attached to the columnar member 132 via the set plate 122. The front end of the crash can 112 is connected to the vicinity of the right end of the bumper beam 160.

  When the automobile collides with an object at a portion between the crash cans 111 and 112, the crash cans 111 and 112 are compressed and deformed to absorb the impact force. The impact force that could not be absorbed by the crash cans 111 and 112 is transmitted to the front side members 151 and 152 through the columnar members 131 and 132. With respect to this embodiment, the shock absorber is exemplified by crash cans 111 and 112. Regarding the present embodiment, the crash cans 111 and 112 are connected to the columnar members 131 and 132 via the set plates 121 and 122. However, the impact absorbing portion may be an impact absorbing structure formed integrally with the columnar members 131 and 132. The principle of the present embodiment is not limited to a specific structure of the shock absorber.

  Since the front side members 151 and 152 are hollow rods that extend straight as a whole, they are not easily deformed even if an impact force is transmitted. The impact force is transmitted to the support structure 170 through the front side members 151 and 152.

  The support structure 170 includes connecting pins 171, 172, and 173. The support structure 170 is connected to a vehicle body located above the subframe 100 via connection pins 171, 172, and 173.

  The support structure 170 has the highest rigidity in the subframe 100. Therefore, the impact force transmitted to the support structure 170 is transmitted to the connecting pins 171, 172, and 173 while being hardly absorbed by the support structure 170. As a result, the connecting pins 171, 172, 173 are damaged, and the subframe 100 is separated from the vehicle body. Therefore, the impact force applied to the subframe 100 is difficult to be transmitted to the passenger compartment (not shown).

  Since the horizontal cross sections of the columnar members 131 and 132 have not only a predetermined width in the vehicle width direction but also a predetermined length in the direction from the set plates 121 and 122 to the rear, the columnar members 131 and 132 High rigidity is provided to the attachment site of the crash cans 111 and 112. If the impact force applied to the bumper beam 160 between the crash cans 111 and 112 is not so great, only the crash cans 111 and 112 are compressed and deformed, and other parts (for example, the columnar members 131 and 132, the front side members 151, 152 and / or the protruding members 141 and 142) are not easily deformed.

  The SOL collision means that the left end portion of the bumper beam 160 (that is, the portion on the left side of the crash can 111) or the right end portion of the bumper beam 160 (that is, the portion on the right side of the crash can 112) collides with the object. The SOL collision hardly causes compressive deformation of the crash cans 111 and 112. At this time, the object collides with one of the projecting members 141 and 142.

  The protruding member 141 is connected to the outer surface of the front side member 151. Therefore, the impact force generated due to the collision of the object with the protruding member 141 acts on the outer surface of the front side member 151. As a result, the front side member 151 is bent rightward. Alternatively, the front side member 151 is folded by an impact force. Therefore, the impact force is difficult to be transmitted to the passenger compartment.

  The protruding member 142 is connected to the outer surface of the front side member 152. Therefore, the impact force generated due to the collision of the object with the protruding member 142 acts on the outer surface of the front side member 152. As a result, the front side member 152 is bent leftward. Alternatively, the front side member 152 is folded by an impact force. Therefore, the impact force is difficult to be transmitted to the passenger compartment.

  FIG. 2 is an enlarged horizontal sectional view of the subframe 100. FIG. 3 is a schematic exploded perspective view of the subframe 100. The subframe 100 is further described with reference to FIGS. 1 to 3.

  As shown in FIG. 2, the columnar member 131 includes a left mounting wall 231, a right mounting wall 232, a left side wall 233, a right side wall 234, and a rear wall 235. The front surfaces of the left mounting wall 231 and the right mounting wall 232 are along one virtual vertical plane (not shown). The set plate 121 is in contact with the front surfaces of the left mounting wall 231 and the right mounting wall 232. The set plate 121 is fixed to the left mounting wall 231 and the right mounting wall 232 by screws or other appropriate fixing tools. As a result, the crush can 111 connected to the set plate 121 is supported by the left mounting wall 231 and the right mounting wall 232. With respect to this embodiment, the support front end is illustrated by a left mounting wall 231 and a right mounting wall 232.

  The rear wall 235 is located behind the left mounting wall 231 and the right mounting wall 232. The left side wall 233 is bent forward from the left edge of the rear wall 235. The left mounting wall 231 is bent leftward from the front end of the left side wall 233. The right side wall 234 is bent forward from the right edge of the rear wall 235. The right side wall 234 is located on the opposite side of the left side wall 233. The right mounting wall 232 is bent rightward from the front end of the right side wall 234. With respect to this embodiment, the inner mounting wall is illustrated by the right mounting wall 232. The outer mounting wall is exemplified by the left mounting wall 231. The outer side wall is exemplified by the left side wall 233. The inner wall is illustrated by the right side wall 234.

  FIG. 4 is a schematic plan view of the front side member 151. The front side member 151 will be described with reference to FIGS.

  As shown in FIG. 4, the front side member 151 includes a left front end 251 and a right front end 252. The right front end 252 is located in front of the left front end 251.

  As shown in FIGS. 2 and 3, the left front end 251 is abutted against the rear wall 235 and overlaps the substantially right half of the lower portion of the rear wall 235. The right front end 252 is welded to the rear surface of the right mounting wall 232. The right mounting wall 232 is sandwiched between the right front end 252 and the set plate 121. With respect to this embodiment, the outer front end is illustrated by the left front end 251. The inner front end is exemplified by the right front end 252.

  Since the left front end 251 is welded to the right side from the intermediate position of the rear wall 235 in the vehicle width direction, unlike the prior art, it does not protrude leftward from the left edge of the rear wall 235. Therefore, even if the front side member 151 extends rearward substantially straight from the left front end 251 and the right front end 252, the steering space described with reference to FIG. 1 is sufficiently wide.

  Since the front side member 151 extends rearward substantially straight from the left front end 251 and the right front end 252, the impact force received by the crash can 111 does not concentrate on a part of the front side member 151, It is transmitted rearward substantially straight along the member 151. Therefore, the front side member 151 is not easily deformed by the impact force received by the crash can 111.

<Other features>
The designer can give various features to the above-described arrangement structure. The features described below do not limit in any way the design principles described in connection with the above-described embodiments.

(Structure of front side member)
The front side member may be formed using a plurality of panel members. A front side member formed using a plurality of panel members will be described below.

  As shown in FIG. 4, the front side member 151 includes a left panel 253 and a right panel 254. The left panel 253 forms the left front end 251 described above. The right panel 254 forms the right front end 252 described above. The left panel 253 extends substantially straight rearward from the left front end 251. The right panel 254 extends substantially straight rearward from the right front end 252. For this embodiment, the outer panel is illustrated by the left panel 253. The inner panel is illustrated by the right panel 254.

  As shown in FIG. 3, the left panel 253 has a U-shaped cross section. The left panel 253 includes a left wall portion 351, an upper wall portion 352, and a lower wall portion 353. The left wall portion 351 faces the left front wheel (not shown) and forms the boundary of the steering space (see FIG. 1). The upper wall portion 352 is bent rightward from the upper edge of the left wall portion 351. The lower wall portion 353 is bent rightward from the lower edge of the left wall portion 351.

  As shown in FIG. 3, the right panel 254 has a U-shaped cross section. The right panel 254 includes a right wall portion 354, an upper wall portion 355, and a lower wall portion 356. The right wall part 354 is located on the opposite side of the left wall part 351. The upper wall portion 355 is bent leftward from the upper edge of the right wall portion 354. The lower wall portion 356 is bent leftward from the lower edge of the right wall portion 354.

  FIG. 3 shows the weld lines WL1 and WL2. The right edge of the upper wall portion 352 of the left panel 253 is welded along the weld lines WL1 and WL2 to the left edge of the upper wall portion 355 of the right panel 254. Similarly, the right edge of the lower wall portion 353 of the left panel 253 is welded to the left edge of the lower wall portion 356 of the right panel 254. As a result, a hollow rod used as the front side member 151 is formed.

  The hollow bar formed by the left panel 253 and the right panel 254 has a size larger in the vertical direction than in the vehicle width direction. Although the front side member 151 is narrow in the vehicle width direction, the front side member 151 is thick in the vertical direction, and thus can have great rigidity.

  The left panel 253 and the right panel 254 having a U-shaped cross section can be formed from a high-tensile steel plate having a tensile strength exceeding 480 MPa by a general bending process. Therefore, the front side member 151 can have sufficient rigidity to withstand the impact force received by the crash can 111.

  As shown in FIG. 4, the right panel 254 includes joint edges 357 and 358 that extend forward beyond the left front end 251 of the left panel 253. The joining edge 357 is a part of the left edge of the upper wall portion 355 of the right panel 254. The joining edge 358 located below the joining edge 357 is a part of the left edge of the lower wall portion 356 (see FIG. 3) of the right panel 254. The joining edges 357 and 358 are welded to the right side wall 234 of the columnar member 131 described with reference to FIG.

(Structure of protruding member)
The protruding member may be formed by bending a thin plate. The protruding member formed by bending the thin plate will be described below.

  As shown in FIG. 3, the protruding member 141 includes a swash plate portion 241, an upper plate portion 242, and a lower plate portion 243. The swash plate portion 241 includes a rear end edge 244 and a front end edge 245 opposite to the rear end edge 244. The swash plate portion 241 extends obliquely leftward and forward from the rear end edge 244 toward the front end edge 245.

  FIG. 3 shows a weld line WL3 located behind the left front end 251. FIG. The rear end edge 244 is welded to the left wall portion 351 of the left panel 253 at the weld line WL3. As shown in FIG. 4, the front end edge 245 is located directly behind the left end of the left mounting wall 231.

  The upper plate portion 242 is a substantially horizontal plate portion that is bent from the upper edge of the swash plate portion 241. The upper plate portion 242 includes a first edge 341, a second edge 342, a third edge 343, and a fourth edge 344. The first edge 341 extends along the upper wall portion 352 of the left panel 253. The second edge 342 is bent from the front end of the first edge 341 and extends to the left. The third edge 343 is bent from the left end of the second edge 342 and extends forward. The fourth edge 344 is bent from the front end of the third edge 343 and extends to the left.

  FIG. 3 shows weld lines WU1, WU2, WU3, WU4. The first edge 341 is welded to the upper wall portion 352 of the left panel 253 along the weld line WU1 formed in the section from the weld line WL3 to the left front end 251 on the upper wall portion 352 of the left panel 253. The second edge 342 is welded to the rear wall 235 along the weld line WU2 on the rear wall 235 of the columnar member 131. The third edge 343 is welded to the left side wall 233 along the weld line WU3 on the left side wall 233 of the columnar member 131. The fourth edge 344 is welded to the left mounting wall 231 along the weld line WU4 on the left mounting wall 231 of the columnar member 131.

  The lower plate portion 243 is a substantially horizontal plate portion that is bent from the lower edge of the swash plate portion 241. The lower plate portion 243 includes a first edge 441, a second edge 442, a third edge 443, and a fourth edge 444. The first edge 441 of the lower plate portion 243 is substantially parallel to the first edge 341 of the upper plate portion 242. The first edge 441 of the lower plate part 243 is welded to the lower wall part 353 of the left panel 253. The second edge 442 of the lower plate portion 243 is bent from the front end of the first edge 441 of the lower plate portion 243 and extends substantially parallel to the second edge 342 of the upper plate portion 242. The third edge 443 of the lower plate portion 243 is bent from the left end of the second edge 442 of the lower plate portion 243 and extends substantially parallel to the third edge 343 of the upper plate portion 242. The fourth edge 444 of the lower plate portion 243 is bent from the front end of the third edge 443 of the lower plate portion 243 and extends substantially parallel to the fourth edge 344 of the upper plate portion 242.

  FIG. 3 shows weld lines WB2, WB3, and WB4. The second edge 442 of the lower plate portion 243 is welded to the rear wall 235 along the weld line WB2 on the rear wall 235 of the columnar member 131. The third edge 443 of the lower plate portion 243 is welded to the left side wall 233 along the weld line WB3 on the left side wall 233 of the columnar member 131. The fourth edge 444 of the lower plate portion 243 is welded to the left mounting wall 231 along the weld line WB4 on the left mounting wall 231 of the columnar member 131.

  FIG. 3 shows a weld line WL4 between the weld lines WU2 and WB2. Welding lines WU2 and WB2 extend substantially horizontally, while welding line WL4 extends substantially vertically. The left front end 251 of the left panel 253 is welded to the rear wall 235 of the columnar member 131 along the weld line WL4.

  The weld line WL4 extends in the vertical direction at a substantially intermediate position of the rear wall 235 in the vehicle width direction. Therefore, the left front end 251 of the left panel 253 contacts the lower right half of the rear wall 235 of the columnar member 131. The right ends of the welding lines WU2 and WB2 are located on the vertical line of the welding line WL4. Therefore, the protruding member 141 covers the left half surface of the lower part of the rear wall 235 of the columnar member 131. With respect to this embodiment, the first region is illustrated by the lower right half of the rear wall 235. The second region is exemplified by the lower left half of the rear wall 235.

(Vulnerable part of front side member)
The front side member may have a fragile portion that is more fragile than other parts of the front side member. If the fragile portion is formed on the front side member, the front side member that receives the force from the projecting member is easily bent and deformed at the fragile portion, and is difficult to bend and deform at other portions. Since the bending deformation position of the front side member at the time of the SOL collision is substantially determined by the weak part, the designer can easily predict the deformation pattern of the front body structure at the time of the SOL collision. An exemplary fragile portion of the front side member is described below.

  FIG. 5 is a schematic horizontal sectional view of a part of the left wall portion 351 of the left panel 253. The weak part is described with reference to FIGS. 1, 3, and 5.

  As shown in FIG. 5, the shallow groove 451 extending vertically is formed in the left wall portion 351. As a result of the formation of the shallow groove 451, the left wall portion 351 is specifically thinned at the site where the shallow groove 451 is formed. That is, the left wall portion 351 is specifically fragile in the shallow groove 451.

  As shown in FIG. 3, the shallow groove 451 is located behind the weld line WL3 to which the rear end edge 244 of the protruding member 141 is welded. When the SOL collision occurs, the rear end edge 244 of the protruding member 141 pushes the left wall portion 351 to the right. Since the front end of the front side member 151 is fixed to the columnar member 131 and the rear end of the front side member 151 is connected to the support structure 170 (see FIG. 1), the rear end edge of the protruding member 141 When 244 pushes the left wall portion 351 to the right, the front side member 151 is deformed so as to bend to the right. As described above, the left wall portion 351 is specifically fragile in the shallow groove 451. In addition, since the shallow groove 451 is separated rearward from the weld line WL3, the left wall portion 351 is greatly bent and deformed in the shallow groove 451. Therefore, the left wall portion 351 cannot withstand the stress caused by the rightward deformation of the front side member 151, and undergoes plastic deformation or destructive deformation in the shallow groove 451.

  In the present embodiment, the fragile portion is formed by the shallow groove 451. However, the fragile portion may have another structure. For example, a through hole may be formed instead of the shallow groove 451. Alternatively, other structures that cause a change in stiffness may be formed in place of the shallow grooves 451. The principle of this embodiment is not limited to a specific structure for forming the fragile portion.

(Cross member)
With respect to the above-described embodiment, the front side member is welded to the columnar member at a position biased inward in the vehicle width direction. Therefore, even when a frontal collision in which the crash can is compressed and deformed, a force that displaces the front side member inward is likely to occur. The front vehicle body structure may include a cross member that resists a force that displaces the front side member inward. An exemplary cross member is described below.

  FIG. 6 is a schematic side view of the subframe 100. The subframe 100 is described with reference to FIGS. 1 to 3 and FIG. 6.

  As shown in FIG. 1, the subframe 100 includes two connecting members 181 and 182. The connecting member 181 is installed at the upper end of the left columnar member 131. The connecting member 182 is installed at the upper end of the right columnar member 132.

  FIG. 6 shows the main frame MFM. The main frame MFM is located above the subframe 100. The connecting members 181 and 182 described with reference to FIG. 1 are fitted into the lower surface of the main frame MFM together with the connecting pins 171, 172, and 173. As a result, the subframe 100 is connected to the main frame MFM. With respect to the present embodiment, the vehicle body is exemplified by the main frame MFM.

  As shown in FIG. 3, the connecting member 181 includes a substrate 183 and connecting pins 184. The substrate 183 may be welded to the upper edge of the left wall 233, the upper edge of the right wall 234 (see FIG. 2), and the upper edge of the rear wall 235. The connecting pin 184 is a round bar-like member that protrudes upward from the upper surface of the substrate 183. FIG. 3 shows the center line CTL of the connecting pin 184. With respect to the present embodiment, the connection position between the main frame MFM and the connecting member 181 may be represented by the position of the center line CTL.

  FIG. 7 is a schematic plan view of a part of the subframe 100. The subframe 100 is further described with reference to FIGS. 1 and 7.

  As shown in FIG. 1, the subframe 100 includes a cross member 190 that extends between the front side members 151 and 152. Cross member 190 includes a trailing edge 191 and a leading edge 192. Each of the rear edge 191 and the front edge 192 extends in the vehicle width direction.

  As shown in FIGS. 1 and 7, the trailing edge 191 extends linearly, while the leading edge 192 curves forward near the front side member 151 as shown in FIG. 7. Since the cross member 190 becomes wider near the front side member 151, a long weld length between the cross member 190 and the right panel 254 of the front side member 151 can be obtained.

  As shown in FIG. 7, the left end of the rear edge 191 of the cross member 190 is located between the front line member 151 between the center line CTL of the connecting pin 184 and the rear end edge 244 of the protruding member 141 in the vehicle front-rear direction. To the right wall 354 of the right panel 254. Since the rear edge 191 of the cross member 190 is positioned in front of the rear end edge 244 of the projecting member 141 that applies a force to bend the front side member 151 to the right during the SOL collision, the rear end edge 244 of the projecting member 141 is The bending of the shallow groove 451 formed at the rear is hardly hindered by the cross member 190.

  Since the front side member 151 is attached to the right side with respect to the columnar member 131, the front end of the front side member 151 acts to the right when a frontal collision occurs in which the crash can 111 is compressed. It is easy to receive. Since the cross member 190 resists a force acting rightward, the front side member 151 hardly deforms rightward. Therefore, the force that could not be absorbed by the crash can 111 is smoothly transmitted to the support structure 170 through the front side member 151.

  The various features described above may be combined or modified to suit the overall design of various vehicles.

  With respect to the above-described embodiments, the joining between the protruding member, the front side member, and the columnar member depends on the welding technique. However, other techniques (eg, rivets and screws) may be utilized with or instead of welding.

  The principle of the above-described embodiment is suitably used for subframes mounted on various vehicles.

100 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Sub frame (Front body structure)
111, 112 ... Crash can (shock absorbing part)
131, 132 ... Columnar members 141, 142 ... Projecting members 151, 152 ...・ ・ ・ ・ ・ ・ ・ ・ Front side members 181 and 182 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Connecting member 190 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・・ Cross member 191 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Rear edge 231 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Left mounting wall (support Front end, outer mounting wall)
232 ........... Right mounting wall (support front end, inner mounting wall)
233 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Left side wall (outer wall)
234 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Right side wall (inner wall)
235 ... rear wall 244 ... rear edge 251 ...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Left front end (outer front end)
252 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Right front end (inner front end)
253 ......... Left panel (outer panel)
254 ... Right panel (inner panel)
451 ..... shallow groove (fragile part)

Claims (7)

A front body structure of an automobile having an impact absorbing portion that absorbs an impact force,
A columnar member having a support front end for supporting the shock absorber, and a rear wall located behind the support front end;
A protruding member protruding outward in the vehicle width direction of the automobile from the columnar member;
A front side member that extends forward so as to form a boundary of a steering space that allows a change in the direction of the front wheels of the automobile and to which the protruding member is attached,
The front side member is connected to the outer front end butted against the rear wall without projecting outward from the rear wall in the vehicle width direction, and to the support front end. A front vehicle body structure including an inner front end located inside the outer front end. The front side member includes an outer panel extending rearward from the outer front end, and an inner panel extending rearward from the inner front end,
Each of the outer panel and the inner panel has a U-shaped cross section,
The front vehicle body structure according to claim 1, wherein the outer panel is joined to the inner panel to form a hollow rod used as the front side member. The projecting member includes a rear end edge joined to the outer panel behind the outer front end,
The front body structure according to claim 2, wherein the outer panel includes a specifically weakened weak part formed at a position rearward of the rear end edge. A connecting member for connecting the columnar member to a vehicle body located above the columnar member;
A cross member having a rear edge extending inward in the vehicle width direction from the inner panel between a connection position of the vehicle body and the connection member and the rear end edge of the protruding member. 3. The front vehicle body structure according to 3. The protruding member is joined to the outer panel in at least a part of a section from the rear end edge to the outer front end,
5. The front portion according to claim 3, wherein the rear wall includes a first region against which the outer front end is abutted, and a second region adjacent to the first region and covered by the protruding member. Body structure. The columnar member includes an inner wall joined to the inner panel projecting forward from the outer front end, and an outer wall located on the opposite side of the inner wall and to which the projecting member is joined,
The support front end includes an inner mounting wall bent inward in the vehicle width direction from the inner wall, and an outer mounting wall bent outward in the vehicle width direction from the outer wall,
The inner front end is joined to the inner mounting wall,
The front body structure according to claim 2, wherein the protruding member is joined to the outer wall. The front vehicle body structure according to any one of claims 2 to 6, wherein the hollow rod body has a dimension larger in a vertical direction than in the vehicle width direction.

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